/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    font-size: 24px;
    font-weight: bold;
    color: #4A90E2;
}

.nav-logo i {
    margin-right: 10px;
    font-size: 28px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

.nav-menu a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-menu a:hover {
    color: #4A90E2;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #4A90E2;
    transition: width 0.3s ease;
}

.nav-menu a:hover::after {
    width: 100%;
}

.nav-buttons {
    display: flex;
    gap: 15px;
}

.btn-login, .btn-register {
    padding: 10px 20px;
    border: none;
    border-radius: 25px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-login {
    background: transparent;
    color: #4A90E2;
    border: 2px solid #4A90E2;
}

.btn-login:hover {
    background: #4A90E2;
    color: white;
}

.btn-register {
    background: #4A90E2;
    color: white;
}

.btn-register:hover {
    background: #357ABD;
    transform: translateY(-2px);
}

/* 主页横幅 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 100px 0 50px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="50" cy="50" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
    opacity: 0.3;
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
    position: relative;
    z-index: 2;
}

.hero-content h1 {
    font-size: 3.5rem;
    font-weight: 700;
    color: white;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-content p {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 30px;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 20px;
}

.btn-primary, .btn-secondary {
    padding: 15px 30px;
    border: none;
    border-radius: 30px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: #FF6B6B;
    color: white;
    box-shadow: 0 10px 30px rgba(255, 107, 107, 0.3);
}

.btn-primary:hover {
    background: #FF5252;
    transform: translateY(-3px);
    box-shadow: 0 15px 40px rgba(255, 107, 107, 0.4);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: #667eea;
    transform: translateY(-3px);
}

.hero-image {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
}

.floating-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 20px;
    padding: 20px;
    margin: 10px;
    text-align: center;
    color: white;
    animation: float 6s ease-in-out infinite;
}

.floating-card:nth-child(2) {
    animation-delay: 2s;
}

.floating-card i {
    font-size: 2rem;
    margin-bottom: 10px;
    display: block;
}

.floating-card span {
    font-weight: 600;
    font-size: 1.1rem;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

/* 课程部分 */
.courses {
    padding: 100px 0;
    background: #f8f9fa;
}

.courses h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: #333;
}

.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
}

.course-card {
    background: white;
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
}

.course-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.15);
}

.course-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.course-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease;
}

.course-card:hover .course-image img {
    transform: scale(1.1);
}

.course-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: #FF6B6B;
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
}

.course-content {
    padding: 25px;
}

.course-content h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: #333;
}

.course-content p {
    color: #666;
    margin-bottom: 20px;
    line-height: 1.6;
}

.course-meta {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    font-size: 0.9rem;
    color: #888;
}

.course-meta span {
    display: flex;
    align-items: center;
    gap: 5px;
}

.course-price {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.price {
    font-size: 1.5rem;
    font-weight: bold;
    color: #4A90E2;
}

.btn-enroll {
    background: #4A90E2;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-enroll:hover {
    background: #357ABD;
    transform: translateY(-2px);
}

/* 教师团队 */
.teachers {
    padding: 100px 0;
    background: white;
}

.teachers h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: #333;
}

.teacher-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
}

.teacher-card {
    text-align: center;
    padding: 40px 20px;
    border-radius: 20px;
    background: #f8f9fa;
    transition: all 0.3s ease;
}

.teacher-card:hover {
    background: white;
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.1);
    transform: translateY(-5px);
}

.teacher-avatar {
    width: 120px;
    height: 120px;
    margin: 0 auto 20px;
    border-radius: 50%;
    overflow: hidden;
    border: 4px solid #4A90E2;
}

.teacher-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.teacher-card h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #333;
}

.teacher-title {
    color: #4A90E2;
    font-weight: 600;
    margin-bottom: 15px;
}

.teacher-desc {
    color: #666;
    margin-bottom: 20px;
    line-height: 1.6;
}

.teacher-stats {
    display: flex;
    justify-content: center;
    gap: 20px;
    font-size: 0.9rem;
    color: #888;
}

/* 统计部分 */
.stats {
    padding: 80px 0;
    background: linear-gradient(135deg, #4A90E2 0%, #357ABD 100%);
    color: white;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    text-align: center;
}

.stat-item i {
    font-size: 3rem;
    margin-bottom: 20px;
    opacity: 0.8;
}

.stat-item h3 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

.stat-item p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* 关于我们 */
.about {
    padding: 100px 0;
    background: #f8f9fa;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-text h2 {
    font-size: 2.5rem;
    margin-bottom: 30px;
    color: #333;
}

.about-text p {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 30px;
    line-height: 1.8;
}

.about-features {
    list-style: none;
}

.about-features li {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
    font-size: 1.1rem;
    color: #333;
}

.about-features i {
    color: #4A90E2;
    margin-right: 15px;
    font-size: 1.2rem;
}

.about-image img {
    width: 100%;
    border-radius: 20px;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.1);
}

/* 联系我们 */
.contact {
    padding: 100px 0;
    background: white;
}

.contact h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: #333;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 20px;
}

.contact-item i {
    font-size: 2rem;
    color: #4A90E2;
    width: 60px;
    text-align: center;
}

.contact-item h3 {
    font-size: 1.2rem;
    margin-bottom: 5px;
    color: #333;
}

.contact-item p {
    color: #666;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-form input,
.contact-form textarea {
    padding: 15px;
    border: 2px solid #e9ecef;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: #4A90E2;
}

.contact-form button {
    background: #4A90E2;
    color: white;
    border: none;
    padding: 15px;
    border-radius: 10px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.contact-form button:hover {
    background: #357ABD;
    transform: translateY(-2px);
}

/* 页脚 */
.footer {
    background: #2c3e50;
    color: white;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    color: #4A90E2;
}

.footer-section p {
    color: #bdc3c7;
    line-height: 1.6;
    margin-bottom: 20px;
}

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section ul li a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #4A90E2;
}

.social-links {
    display: flex;
    gap: 15px;
}

.social-links a {
    display: inline-block;
    width: 40px;
    height: 40px;
    background: #4A90E2;
    color: white;
    text-align: center;
    line-height: 40px;
    border-radius: 50%;
    transition: all 0.3s ease;
}

.social-links a:hover {
    background: #357ABD;
    transform: translateY(-3px);
}

.subscribe-form {
    display: flex;
    gap: 10px;
}

.subscribe-form input {
    flex: 1;
    padding: 10px;
    border: none;
    border-radius: 5px;
    font-size: 0.9rem;
}

.subscribe-form button {
    background: #4A90E2;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    transition: background 0.3s ease;
}

.subscribe-form button:hover {
    background: #357ABD;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #34495e;
    color: #bdc3c7;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-content h1 {
        font-size: 2.5rem;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .course-grid {
        grid-template-columns: 1fr;
    }
    
    .teacher-grid {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 2rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .course-meta {
        flex-direction: column;
        gap: 10px;
    }
    
    .course-price {
        flex-direction: column;
        gap: 15px;
        align-items: stretch;
    }
} 